/**
 * @file arm.c
 *
 */
/* Copyright (C) 2018 by Arjan van Vught mailto:info@orangepi-dmx.nl
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <stdbool.h>
#include <stdio.h>

#include "arm/synchronize.h"

bool arm_install_handler(unsigned routine, unsigned *vector) {
	unsigned vector_table;
	asm volatile ("mrc p15, 0, %0, c12, c0, 0" : "=r" (vector_table));

	const unsigned vec = (((routine - vector_table) - (unsigned) vector - 0x8) >> 2);

	if (vec & 0xff000000) {
		return false;
	}

	const unsigned v = (unsigned) vector + vector_table;
	*(unsigned *) v = (0xea000000 | vec);

	invalidate_instruction_cache();
	isb();

	return true;
}

